PLE-5690

A 45-year-old female presents with a 4-day history of an acutely painful right-sided goiter. She has no previous history of thyroid disease and clinically appears euthyroid. A thyroid gland biopsy would reveal disruption of thyroid follicles with extravasation of colloid, leading to a polymorphonuclear infiltrate. A granulomatous reaction may be seen. What is the most likely diagnosis?